Method of making fluid discharge nozzles



March 13, 1945. McDOUGAL 2,371,532

METHOD OF'MAKING FLUID DISCHARGE NOZZLE Filed Aug. 25, 1941 Patented Mar. 13, 1945 METHOD OF MAKING FLUID DISCHARGE NOZZLES v Taine G. McDougal, Flint, Mich. l F Application August 25, 1941, Serial No. 408,187

3 Claims. (01. 29-157) This invention relates to a one-piece fluid discharge nozzle, preferably assembled to a flange to render the unit suitable for demountable attachment. It also relates to an exceptionally economical method offabricating such nozzles.

For overhead irrigation ofland areas it is necessary to direct the water stream, preferably through a nozzle, upward and outward from the distribution point or points and, furthermoreyto cause the directing nozzle to rotate continuously or intermittently about a provided pivot in order to irrigate a generated area. To realize maximum throwing distance with a given pressure at the nozzle, it is necessary to remove any turb-u lence present 'in the water stream as it is delivered to the nozzle and for this purpose it is practice to provide straighteners in the form of a pack of small tubes positioned inside and parallel to the nozzle. 1

For the irrigation of large land areas water pressures of the order of 100 to 180 lbs/sq. in. are involved and a desirable size of the distributing nozzle is of the order of forty inches in length, three inches in diameter at its up-stream end and one and one-half inches diameter at the orifice end. It has been the practice, because of the length of such nozzles, to build them up of flanged sections bolted together with sealing gaskets. In one such arrangement the nozzle has been composed of three sections, the up-stream section being a straight 3-inch pipe flanged at one end for connection to the water source and at the other end for connection to amiddle flanged casting containing a tapered hole. The

third or orifice section is an internally machined casting flanged at one end for attachment to the middle section and having a discharge orifice at the other end. Such a nozzle Weighs approximately 20 pounds and is therefore unwieldy besides being subject to leakage at the joints.

The aligned middle and orifice sections may be so joined tothe up-stream section that their common axis is inclined horizontally in respect-to the horizontal axis of the latter. A stream, discharging through the nozzle thus assembled, is deflectedfrom its straight path at the point of the nozzles horizontal inclination and the force of deflection causes the pivoted nozzle to revolve in the ease of continuous discharge, or to index in the case of intermittent discharge.

I recognize as old in the art, a nozzle whose inner bore consists respectively of a straight section, a truncated conical section and an orifice section and embodying a pack of straighteners to remove turbulence from a fluid stream pass ing through it, and also recognize that it is not new to incline horizontally the tip end of a nozzle to effect rotation; and I do not claimsuch'to be .a part of my invention. I

It is the purpose of my invention, among other things, to provide means for accurately shaping the bore of a fluid discharge nozzle, whereby quantities of such nozzles may be produced with substantial savings over methods hitherto employed. A further purpose 'of my invention'is to i provide in said bore a shoulder or seat against which a straightener pack may abut to prevent said pack in service from wedging into the conical bore next down-stream, consequently constricting or closing openings of individual straightener tubes. Other advantages of my invention will become apparent from the description which follows.

g In carrying out my invention, a mandrel pref; I

erably of steel is shaped by machining in a lathe or by other suitable means, to conform to the desired internal contour of the nozzle. The mandrel is fixed to a drive suitable to rotate it about its .longitudinal axis. steel. or copper being preferred but. of anyiother suitable metal or alloy, is placed over the mandrel, the internal diameter of the pipe corresponding to the. maximum external diameter of the mandrel. The mandrel and pipe are :then rotated simultaneously and preferably heat is applied by oxy-acetylene torch or byother convenient means to soften the metal to a more workable state; and the pipe is'spun against the mandrel using hand tools well known in the metal-spinning art. Although I have found'the use of hand tools efiective, mechanically mounted rollers could also be used. Thespunnozzle is removed from the mandrel and next mounted on a stub mandrel, as later described in detail, for bending to its final form.

In the drawing: Figure 1 is a side elevation of apparatus for spinning a tubular blank 'to form the nozzle, the

A suitable length of 19 1 8 Referring to Figure l, the mandrel consists of a flange 2, internally threaded atl for attachment to the live center (not shown) of a lathe or to other suitable driving means. The cylindrica-l section 3 of the mandrel is of a diameter to conform to the internal diameter of the pipe 4. Other sections of the mandrel are, a shoulder 5, a truncated conical section 6, and t p I. The tip section I is provided with a bore 8 to receive the dead center 9 the latter mounted preferably on the tail stock (not shown) 'of the lathe or on other suitable support. .The idling center 40 is interposed between the right end of pipe 4 and the dead center 9, to afford means of pressing said pipe aga nst driving flange 2 thus assuring frictional drive of said pipe until such time .as shoulder 5 and at least a portion of section 6 have established frictional driving contact with the partially spun pipe; center It! may then removed and center 9 advanced to engage the hole 8 to permit completion oi-the spinning operation.

In Figure 3 is shown in section, a stub arbor '3' and spun nozzle 4', the latter being in position to be slowly revolved through fr ctional contact with the former which is preferably attached to a lathe center as described in connection with Fig. 1. The spun nozzle l is preferably'heated, (while slowly rotating), for a short distance along its length toward the orifice-from .-but adjacent to, end 13 of the stub arbor, before applying pressure while stationary by some suitable means to bend the end 14 so its longitud nal axis will be inclined from its original straight alignment with the remainder of the nozzle length. Extension of the. stub arbor beyond shoulder 5' of the nozzle. to position I3, aflords support to said shoulder and prevents deformation thereof during the bending operation. Bending pressure may conveniently be applied by slipping a pipe !5, as shown, over the nozzle tip, The shoulder 5 in the-finished article serves to position the straightener I2.

Nozzles made by the above described methods are. because of their continuous one-piece structure, free from troublesomeblow-out of gaskets with attendant service cost and service interruptions. Such failures are not uncommon where high pressures are involved as is the case in economically irrigating large areas. They maybe manufactured in quantity from ordinary commercial metal pipe, spun over a once-machined mandrel, in contrast to the several individually machined or assembled sections formerly necessary for fabrication of each single nozzle' A rigid shoulderof predetermined and controlled dimensions for retention of the straightener pack, and an accurately shaped orifice are realized at extremely low production cost. The actual weight of a nozzle as fabricated and assembled by prior art methods is approximately 20 /2 pounds while a nozzle of thesame inner bore shape and length, as fa'bricatedand assembled by means here disclosed, is approximately eleven pounds. Besides representing a marked cost saving in labor and material, the new lighter-weight nozzle has the advantage of practically halving the objectionable eccentric load imposed upon the nozzles pivoted bearing. l

The article resulting from the practice of the method herein disclosed and claimed forms the subject matter of my divisional application Serial No. 545,135, filed July 15, 1944.

Having described my invention and the manner in which it is performed, I claim:

1. The method of making a bent tapered nozzle which comprises preparing a mandrel having one end of reduced diameter and tapered to conform to the interior of a substantially finished nozzle, mounting a tubular blanket substantially uniform wall thickness on the mandrel, spinning the mandrel while applying a tool to the blank to cause one end thereof to conform in shape to the shape of the reduced portion of the mandrel, removing the blank from the mandrel and applying it to a stub mandrel fitting the interior of .the portion of the blank of original diameter and having a reduced portion extending part way into and fitting the interior of a part of the portion of the blank of reduced diameter, bending the remaining reduced portion of the nozzle to cause its to extend at an angle to the axis of the portion of original diameter, and thereafter removing the blank from the stub mandrel.

2. The method of making a bent tapered nozzle which comprises preparing a mandrel having a main body and one end of reduced diameter and tapered to conform to the interior of a substantially finished nozzle, mounting a tubular blank of substantially uniform wall thickness on the mandrel, spinning the mandrel while heating the blank and applying a tool to the blank to cause one end thereof to conform in shape to the shape .of the reduced portion of the :mandrel and to .form a shoulder between the reduced portion and the main body, removing the blank from the mandrel and applying it to a stub mandrel fitting the interior of :the portion of the blank of .origi nal diameter and having a reduced portion extending part way into and fitting the interior of a part of the portion of the blank .of reduced diameter, bending the remaining reduced portion oi the nozzle to cause its axis to extend at .an angle :to the axis of the portion of original diameter, and thereafter removing the blank from the stub mandrel.

3,. The method of making a bent tapered .noz+ zle which comprises preparing a mandrel having a main body and one end of reduced diameter and tapered to conform to the interior of a substantially finished nozzle, mounting a tubular blank on the mandrel, applying axial pressure to one end of the blank to hold it on the mandrel and thereafter spinning the mandrel while applying a tool to the blank to cause one end thereof to conform in shape to the shape of the reduced portion of the mandrel and to form va shoulder between the reduced portion and the main body, removing the blank from the man. drel and applying it to a stub mandrel fitting the interior of the portion of the blank of original diameter-and having a reduced portion extending past said shoulder and part way into and fitting the interior of a part of the portion of the blank of reduced diameter, heating the blank adjacent said shoulder and bending the remaining reduced portion of the nozzle to causeJi-ts axis to extend at an angle to the axis of the portion of original diameter, and thereafter removing the blank from the stub mandrel. 1

TAINE G. MoDOUGAL. 

